


Friend from Foe

by Philomytha



Category: Rivers of London - Ben Aaronovitch
Genre: Action/Adventure, Gen, Mind Manipulation, Post-Book: Foxglove Summer
Language: English
Status: Completed
Published: 2020-12-18
Updated: 2020-12-18
Packaged: 2021-03-11 02:00:37
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,117
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28117341
Author URL: https://archiveofourown.org/users/Philomytha/pseuds/Philomytha
Summary: Everyone knew about the open day at Casterbrook. Even the Faceless Man.
Comments: 30
Kudos: 123
Collections: Yuletide 2020





	Friend from Foe

**Author's Note:**

  * For [keerawa](https://archiveofourown.org/users/keerawa/gifts).



For a few hours the old school had lived again, but now the silence of the past fifty years was settling back on Casterbrook. The guests had all left, even Sergeant Guleed who had been helping Peter clear up, and Beverley who had been watching and pointing out things they'd missed. The old men--his contemporaries, his juniors--had left early. Hugh himself had only stayed for a few hours under Mellissa's watchful eye. Nightingale finished his drink, set the glass down and looked around, his mind re-populating the empty spaces. There had been almost a hundred guests at Peter's open day, all told: fae and demi-fae and Rivers and practitioners and hedge-wizards and police, not to mention their assorted family and acquaintances. Peter's father had played a few sets, but he'd gone back to London some hours ago as if pulled by an elastic band. Peter's attachment to the city, Nightingale reflected, was something he came by honestly. 

Peter was running a hoover on the gallery, still bright-eyed after the long day, pausing to use a different attachment to clean the alcove at the top. Nightingale stared up at it tiredly. He'd slept in that alcove for over a month: it was out of the draughts, and commanded a view of the great staircase where he'd been working from sunrise to sunset with his chisels. He'd thought he was sane then, but now, with seventy years of perspective, he must have been more than half crazed still. He could have at least slept in one of the dorm rooms, in a bed. The dead wouldn't care either way, and he'd spoken to many dead over the years, so he should know. 

The loud whirring from the machine stopped, and he heard Peter begin to carry it down the back stairs. Just the last few jobs and then it would be over. Peter's jamboree had been held here, under the great wall of names. It wasn't subtle, but then, it didn't need to be. All the magical community, as Peter called them, under his roof, eating at his table. He had formally freed them from obligation, but there was more than one kind of obligation. All these different people had broken bread together, and they had done it under his roof. Under the great wall of the names of the dead. A gift for Hugh, Peter had told him, but it was much more than that. Peter was creating a new order, and thrusting him into the centre of it, the arbiter of right and wrong, the law. He didn't think Peter mistook the other symbolism here, for all he presented it as building a community, creating a network. There were no communities without rules, spoken or unspoken, and by holding his party here, under the eyes of the dead, Peter was very clear about where he placed that authority. 

A clatter from a storecupboard and Peter emerged. Nightingale pushed himself to his feet, aware that he had drunk several more rounds than usual. Tired and emotional, as they said in the press, and he felt all three. Hugh had frankly wept when he'd arrived here, and that had only been the start of the day. Peter was mercifully silent, only saying, "I'll be driving back." 

Nightingale handed him the keys to the Jag and wandered over to the refectory, which had served its original function today with trestle tables laden with Molly's offerings. She'd been busy for weeks preparing for this. All was cleared away now, but the tables were still laid out. Peter yawned and headed in to fold them up, but Nightingale raised his hand. The _formae_ came as easily as reciting a Latin verb, ingrained in him the same way, and the tables folded themselves one by one and flew to their storage cupboard.

"Nice," Peter said. If he'd been more awake, Nightingale might have made him identify the _formae_ he'd used. Instead he found himself saying, "We used to have to do that at the end of every meal." 

Peter muttered something about Hogwarts which Nightingale ostentatiously took no notice of. "Not the prefects," he went on. "By the time you were in the Lower Fourth you were expected to be able to do that one." Another swift combination of _formae_ , and the chairs followed them. 

"You should have come to help sooner," Peter retorted cheerfully. "All that hoovering." 

"We didn't have anything for that. Or hoovers, come to think of it. I recall Deacon trying to conjure a very localised wind to blow crumbs across the floor, but Matron just yelled at him for raising the dust." It was so easy to remember these things, here. He leaned on his staff as Peter finished tidying up around the room and heaved up another black sack of rubbish. 

"I think that's it," he said. "You ready, sir?" 

Nightingale looked around the great hall, then took a deep breath and extinguished the lights. Darkness and silence returned to the building, but Peter was bustling with the double doors, unhooking the catches that had held them open, swinging them shut, fastening the bolt on the first half before going out and closing the school up again. 

"It was a good idea," Nightingale said as he turned the great key in the lock. "A very good idea, Peter." 

As ever, praise disconcerted Peter, and he said, "You say that now, but wait till the hangover sets in." 

"Won't be as bad as that time with Varvara," Nightingale parried, and sat in the passenger seat of the Jag with a sigh. Hangovers were definitely for the young, he'd decided in the aftermath of that, and he'd been careful today. Peter laughed and started the engine. The Jag bumped along the gravel drive to the great gate at the road. The gate was closed, and Peter halted the Jag and put on the handbrake. 

"The Countryside Code," Peter said with a grin. "Ash must have been lecturing someone." He opened the door and jumped out. 

The Jag's headlights played on the gate, and something that was always sleeping with one eye open inside Nightingale woke up. "Peter," he began, but Peter was already crunching over the gravel. 

The entire demi-monde had known about this open day, in London and outside it. Zach Palmer had been here, driving a minivan full of Quiet People. And what Zach knew, Lesley May knew. The party had been conducted under the rules of _pax domus_ , but their Faceless Man would care nothing for that. He had discussed this with Peter, and they had taken security precautions, and nobody who wasn't invited could enter the premises of the school. Could pass the gate...

"Peter, stop!" Nightingale shouted, unfastening his seatbelt and flinging his own door open. 

Peter stopped obediently, but his hand was already on the latch. 

The trap went off. 

Nightingale felt the blast of magic and threw himself sideways, behind the cover of the car door. Peter was hurled back onto the bonnet, but he rolled into the fall and landed on the other side of the car, outside the headlights, on his feet. Nightingale didn't waste more than a half-second on relief, extending his senses--that hadn't been a demon trap, he wasn't sure what it was, but if the Faceless Man was anywhere here... he scanned the woods around them, the road on the other side of the gate. It was only half an hour since the final guests had departed, and the trap hadn't been here then. 

The gates were swinging wildly on their hinges now, one half of the heavy metal frame nearly knocking Peter off his feet as he scrambled up. The Jag's headlights made it harder to see, destroying his night vision, the world outside the illuminated area totally dark. 

A man stepped into the light, and Nightingale reflexively moved, shield coming up, ready to strike. He heard Peter give a shout. "Armed police! Stay where you are!" The man's face was hidden behind a mask. Nightingale took a step forwards, deliberately drawing his attention away from Peter. 

Peter gave another shout and Nightingale braced. The Faceless Man had neither moved nor spoke, but Nightingale could sense him beginning a spell, and he flicked his fingers. To one side he sensed Peter's distinctive _signare_ , and loosed his own attack at the same instant. 

No magical attack had taken Nightingale by surprise for half a century, but as Peter's fireballs swerved around towards him, he only just moved his shield in time. One fireball seared straight past his ear. Peter was getting stronger. A surge of adrenalin went through him at the near-miss. 

"What the hell, Grant?" he shouted, glancing backwards in case there was another enemy behind him who was Peter's real target. But there was nothing there, and Peter had an odd glassy look in his eyes. In the gateway, the Faceless Man said, "Keep it up, Peter," and Peter shot him a disturbingly familiar grin. 

He was seriously regretting his last two drinks now; he wasn't up to par, though he'd fought under worse conditions than this. But never with his own apprentice caught in the middle of it. 

"It was a trap, Peter," he said, letting every drop of magisterial authority he possessed fill his voice even as he kept the rest of his mind on the _lutte sans merci_ , anticipating what the Faceless Man would do next. "It was a trap. You're under a spell." 

It must be some sort of glamour turned into a weapon, confusing Peter as to friend and foe. But the Faceless Man was increasing the complexity of his workings, and Nightingale had to focus on fending them off, spell and counter-spell. The edges of the drive were marked with a row of boulders. He sent a couple of them at the Faceless Man, abandoning subtlety for violence, and dodged backwards to avoid the gate swinging to knock him off his feet. He moved back, out of the light of the Jag's headlights, and not only in the hope that he might preserve his car. Peter had moved to the Faceless Man's side now, and they were advancing on him relentlessly. 

Peter was under a spell of some sort. At Skygarden his other apprentice had turned against him voluntarily, but not this time, of that Nightingale was utterly certain. He heard Peter's voice, taut with anticipation, "We can bring him in this time, sir." Somehow, the glamour had affected Peter, so that when he looked at the Faceless Man, he saw Nightingale instead, and vice versa. It wasn't a spell he'd encountered, but if it was a glamour then it would work the same way as any other glamour. He just had to wait and push and Peter would break through it on his own. 

The Faceless Man was letting Peter stay in front of him, using Peter as a shield, letting Peter lead the attack. He wouldn't attack Peter himself, not as long as Peter remained under his spell. But once Peter broke through the glamour, he'd turn instantly into a hostage for the Faceless Man. 

Nightingale backed into the woods, out of the light, playing for time. He was triply disadvantaged here: not entirely sober, fighting on a time and place of his enemy's choosing, and with Peter as both hostage and attacker. 

The Faceless Man crashed a tree down on him. Nightingale caught it a foot above his own head, set it alight and threw it back, but he had to make it land short so that it wouldn't strike Peter, obstacle rather than projectile weapon. 

Peter was renewing the attack now, his improved _impello palma_ shield nearly catching Nightingale unawares as he fended off the Faceless Man's efforts to set his clothes on fire. He slashed through the shield impatiently, but bit his tongue on a further attempt to tell Peter what had happened to him. Not with the Faceless Man right beside him. He tripped Peter in the hope of separating them, but Peter instantly scrambled up and kept on pushing, his persistence everything Nightingale had always admired in him. 

He couldn't win this battle by fighting. Not with Peter held unknowing hostage. 

Inspiration came as his foot slipped on a patch of mud and Peter raised his hand again. "I surrender!" he shouted, and threw down his staff. 

It was one of the hardest things he'd ever done in his life. "I surrender," he repeated, eyes fixed on Peter. He raised his arms in the classic position, and saw Peter go still.

"You can't trust him," the Faceless Man said urgently. "You know he can't be trusted. There's only one way this can end, Peter, you know that. You might be able to arrest people like Varvara Sidorovna, but him? It's never going to work. 'Killed resisting arrest' is the only way you can keep the peace, and you know it as well as I do." 

"Don't move," Peter said to him in answer, completely ignoring the Faceless Man in a way that Nightingale recognised with grim amusement. It wasn't just him, Peter was like this with anyone he thought was his boss. "If we sense you beginning to perform a spell, my guv here will put a fireball in you, understand?" 

"I swear on my power," Nightingale said clearly. "I won't resist you." 

"In that case," said Peter, "I am arresting you for murder, attempted murder, grievous bodily harm and many other charges. You do not have to say anything, but it may harm your defence if you do not mention when questioned anything you later rely on in court. Anything you do say may be given in evidence." He pulled out a pair of handcuffs that Nightingale hadn't realised he'd been carrying all day, and slowly advanced. Nightingale didn't move, holding his breath. The Faceless Man seemed to hold his breath too. 

Peter put the cuffs on him and pulled him forwards, twisting the cuffs just as Nightingale had taught him to do, to keep a magical enemy off-balance and interfere with his ability to cast a spell. Nightingale relaxed a little when he was standing between Peter and the Faceless Man. 

"Very clever," the Faceless Man said quietly to him. "But the ball's still in my court. Peter," he went on more loudly, "get his staff too. I'd like to take a look at it." 

Peter kept one hand on the cuffs as he stooped to pick up the staff, but the movement was ungainly and he slipped. It was what the Faceless Man had been waiting for, and Nightingale felt the beginnings of a _forma_ , a simple fireball. Peter felt it too, and shouted, "No! Sir, it's okay!" 

The staff was in his hand as he spoke, and the shield Peter cast around him was vastly more powerful than anything the boy had managed before. Nightingale heard Peter's sharp intake of breath. Then he said, "I've got him, we're fine," and pushed Nightingale forwards again, back towards the drive and the car. Back towards the Faceless Man. 

"It will only get harder," said the Faceless Man. "Is this what you want to be doing for the rest of your life?" 

It was fiendishly clever, Nightingale had to admit. Kill him, get Peter to bear the guilt of it, and the Faceless Man could continue with his plans, whatever they were, confident that there was nobody in authority who could stop him. 

"It's what we do," said Peter. "And this time nobody's going to taser me. You're going up the steps this time." 

Nightingale tensed, because there was something different in Peter's voice, the words directed ahead of him. So he wasn't entirely surprised when he felt the staff slip into the palm of his hand, still bound behind his back. 

"I just hope you're right," said the Faceless Man. "But I'm afraid you're too trusting." 

"No," said Peter. "I'm not," and Nightingale raised a wind that blew the Faceless Man ten metres back, so that he landed on the verge of the road, where the brambles all twined their thorny strands around his body. Peter exploded one of his icy water balloons in his face, drenching the mask; Nightingale heard him spluttering and gasping even as he burst free of the thorns. 

Then the Faceless Man threw two trees down across the road and took to his heels. Nightingale sent fireballs after him, but Peter grabbed his arm. "Car! Quick!" 

The rural road that led to Casterbrook was quiet at this hour, but not deserted, and by the sound of it someone was coming along at speed and would collide with the fallen trees in seconds. He and Peter both lifted the trees with _impello_ and dumped them in the field on the far side of the hedge just before the red hatchback flashed past. 

The Faceless Man was out of sight. Gone, if he had any sense. They both scanned the road in the direction he'd fled in, turning around and around for a solid five minutes with no trace of him. Nightingale exhaled slowly, and became aware that his fingers were starting to go numb, holding the staff pinned behind his back. "If you don't want me to snap these--" he said. 

"Oh. Yeah. Sorry." Peter fumbled with the key and released the handcuffs. "I have no idea what he did to me there. I just... it all made sense at the time." 

"He's left the residue of the trap on the gate," Nightingale said. "We can examine it at leisure, later on. It was a clever attack." 

Peter rubbed his eyes and stared at Nightingale as if trying to correct the images in his head. "I was looking at you," he said, "but what I saw was him. Even when you tried to tell me."

"Fortunately for us all," Nightingale said, stretching out his arms and shaking them, "your perceptions may have been confused, but your moral compass was not." 

This time Peter turned that pleased grin on him, and Nightingale felt something settle back down inside him. "When we do finally catch that, that _ethically challenged practitioner_ ," he continued, "we'd better have our preparations finished. Tomorrow we'll make a start on constructing magic-proof cells." 

"You see," said Peter obliquely, "that's how I finally knew. He's the one who's stuck in the past. You're not." He looked back at the bulky shadow of Casterbrook against the night sky. "I think today's proof of that." 

"Let's get this finished up," was all Nightingale said in response, turning to the gate and its residual trap, but as he turned, he let Peter see his smile.


End file.
